SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5adb3efbeeb25637567576a798698d079b84b87babac71179d29be0cbcee773' 
  AND token = 'l7LwGkWzuX1fkYl3Ms+z5EEriOWVO5Zmn/dbAOLUjBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}